Calcite Presoak is designed as a pre-soak to facilitate the quick removal of calcite on brick, block or concrete. Used in conjunction with NMD 80, this combination will ensure the complete removal of calcite. First apply the Calcite Presoak undiluted and allow it to dwell on the surface for approximately five minutes. Repeat this process without rinsing until little pin holes have opened up. Then apply NMD 80 diluted four parts water to one part solution (4:1) without rinsing off the Calcite Presoak; allow a five to ten minute dwell time. Rinse completely to get the desired results.